Buttermilk substitutes, and why the milk-and-lemon trick works

The part that actually matters

Buttermilk does two things in a recipe: it adds acid and it adds a little tang. The acid is the important one.

Most recipes calling for buttermilk also call for baking soda, which a British recipe will list as bicarbonate of soda. Same raising agent, same jar, and it needs an acid to react with. That reaction is what lifts the bake. Swap in plain milk and the soda has nothing to work against, so you get a flat result that can taste faintly soapy.

That is why the milk-and-lemon trick works. You are not imitating buttermilk’s flavour, you are restoring the acid the recipe was designed around.

The same chemistry runs the other way when it is the baking powder you are out of: baking soda plus buttermilk will stand in for it. Baking powder substitutes has the amounts for any quantity your recipe asks for.

The 10-minute fix

Put one tablespoon of lemon juice or plain white vinegar in a measuring jug. Top it up to one cup with milk. Stir once, then leave it alone for ten minutes.

It will look slightly curdled and separated. That is correct. The acid has denatured the milk proteins, which is exactly the reaction you wanted. Do not throw it out and start again.

Five minutes is enough if you are rushing. Longer does no harm.

How much lemon juice or vinegar for the amount you need

Lemon or vinegar? For the rise it makes no difference, because both supply the acid. Lemon leaves a faint citrus note that suits pancakes and cakes. Plain white vinegar disappears completely once baked. Cider vinegar is fine too. Malt and balsamic are not, because they bring flavours of their own.

What to use for what

Pancakes, soda bread, scones, biscuits, most cakes: milk plus lemon juice or vinegar. It is the closest match on consistency and behaves identically with raising agents.

Marinades: yogurt thinned with milk. Buttermilk is a classic chicken marinade because the acid and the calcium together tenderise without turning the meat to mush the way a lemon-heavy marinade does. Thinned Greek yogurt does the same job and clings better.

Dressings: plain yogurt thinned with milk, which gives you the tang and enough body to coat. Plain yoghurt on a British label is the same thing, and here it genuinely does not matter which tub you take: you are thinning it back down anyway, so strained or not makes no difference to the result.

Dairy-free baking: soy milk plus lemon juice. Soy has enough protein to curdle properly. Oat and almond barely thicken, but the acid still does its job on the raising agent, so the bake works even if the liquid looks thin.

Can you use plain milk instead of buttermilk?

For the liquid, yes. For the rise, no, and that is the part that catches people out.

Buttermilk is acidic. Recipes that call for it almost always pair it with baking soda, or bicarbonate of soda on a British recipe, and that raising agent does nothing at all without an acid to react with. Swap in plain milk and you have not made a slightly different pancake, you have removed the reaction that was supposed to lift it. Flat, dense, and nobody can work out why.

The ten-minute fix above solves exactly this by putting the acid back. For the rise it is the same chemistry. What it does not copy is buttermilk’s flavour, which the baking section below covers.

Kefir is the closest thing on the shelf. Cultured, pourable and already acidic, so it goes in 1:1 with nothing added and no waiting. If your shop has it, it is a better answer than anything you can mix yourself.

Yogurt or sour cream, thinned with milk, both work, because both are cultured and acidic. Loosen them to the consistency of single cream first or the batter will be too stiff.

Half and half will not do it, for the same reason plain milk will not. It is richer, not sourer, and richness was never the point.

For fried chicken it is a different job

The buttermilk in a fried chicken brine is not there for lift, so the raising agent problem does not apply. It is there to tenderise, and to give the flour something to cling to.

That makes it the one case where almost anything acidic and pourable works. Milk with a tablespoon of lemon juice, thinned yogurt, or kefir will all brine and coat perfectly well. Plain milk on its own is the only weak choice, and even then the coating sticks; the meat is just less tender.

Buttermilk substitute for baking

The best evidence here is a side-by-side test, not an opinion. King Arthur Baking made biscuits, pancakes and a buttermilk cake with real buttermilk, milk soured with vinegar, milk with cream of tartar, Greek yogurt thinned with milk, and plain milk (King Arthur Baking, 2019).

What it found, in short:

• Every substitute rose and browned like buttermilk in the biscuits and pancakes, except plain milk, which rose less.
• Flavour is where they differ. Buttermilk tasted best, Greek yogurt thinned with milk came closest, and the soured milk versions lacked depth.
• In the cake, every substitute worked except plain milk, which baked darker and denser, because the cake was raised with baking soda.

So pick by how plain the recipe is:

King Arthur’s own best ratio for the yogurt version was one part Greek yogurt to two parts low-fat or skimmed milk.

Can you use buttermilk instead of milk?

In most baking, yes, 1:1. Pancakes, cakes, muffins and quick breads all take it well, with a little extra tang.

Where it goes wrong is a sauce that simmers. Buttermilk curdles in one, because it is acidic and low in fat, so keep it out of a white sauce or a creamy soup that boils.

It is also useful at the end of a carton: buttermilk freezes, and King Arthur suggests freezing it in half-cup portions. It separates when it thaws and is fine to bake with.

Buttermilk and heavy cream

Heavy cream in place of buttermilk works only once you sour it and thin it. Cream is sweet and thick rather than acidic. A quarter cup of heavy cream topped up to a cup with water, plus a tablespoon of lemon juice, gives you something pourable and acidic at around 9 percent fat by our estimate, against buttermilk’s roughly 1 percent. It is a lot richer.

Buttermilk in place of heavy cream does not work for anything that needs cream’s fat. It will not whip, and it splits in a hot sauce. For that swap, see heavy cream substitutes.

Lactose-free and dairy-free buttermilk

Lactose free: lactose-free milk plus lemon juice or vinegar, exactly as the ten-minute fix. It is still cow’s milk, so it curdles and behaves the same way. Cultured buttermilk from the shop is a dairy product that still contains lactose.

Dairy free: soy milk plus lemon juice, because soy has enough protein to curdle convincingly. Oat and almond milk barely thicken, but they still supply the acid to the raising agent, so the bake rises.

Buttermilk in Britain

Buttermilk is sold in British supermarkets, so it is often easier to buy than to fake. If you do make it, British recipes measure in millilitres: put 15 ml of lemon juice in a jug, top it up to 240 ml with semi-skimmed or whole milk, which is the same as the American one cup, and wait ten minutes.

A British recipe will list baking soda as bicarbonate of soda, and plain yogurt as plain yoghurt. Neither changes anything above.

The one that quietly wrecks the macros

Sour cream thinned with milk is a common recommendation and it does work in a cake. But it lands around 155 kcal and 14.7 g fat per 100 g, against roughly 40 kcal and 0.9 g for real buttermilk. That is not a small difference, and no substitute list I checked mentions it.

If you are choosing on macros rather than convenience, skimmed milk with lemon juice is the lightest option and Greek yogurt thinned with milk is the highest-protein one at roughly double buttermilk’s protein.

Values are typical figures, rounded, and vary by brand. They are here for comparing options rather than for precision.